A power supply may function with a wide variety of power sources, including batteries and vehicle power. During transient conditions the input power may rise above or fall below normal operating ranges, and a power supply should be able to withstand these changes. For example, vehicle power has a wide input voltage operating range (e.g., from 6V-32V), whereas battery power has a narrow input voltage operating window (e.g., 10V-16V). Direct current to direct current (DC-DC) converters may be used to manage the wide input voltage operating ranges. DC-DC converters employ a number of switch topologies, which may include a boost converter or a flyback converter. The boost converter may be used to convert a low input voltage supplied by, for example, a battery, to an optimal voltage level greater than the input level. The flyback converter may be used in conjunction with the boost converter to convert a high input voltage supplied by, for example, a vehicle, to an optimal voltage level smaller than the input level. The conversions may yield an efficiency of approximately 70%. The flyback converter may be needed to manage the vehicle power's wide input voltage range and to provide DC isolation between the vehicular source and the end user power converter load, but may not be needed to manage the battery power's input voltage ranges.